Method for producing magnesium alcoholate

ABSTRACT

The purpose of the present invention is to provide a spherical or ellipsoidal magnesium alcoholate having a narrow particle size distribution even when the particle size is small. 
     The present invention provides a method for producing a magnesium alcoholate by adding in a portionwise manner to a reaction system and reacting, metallic magnesium, an alcohol, and at least one of a halogen or a halogen atom-containing compound in the reaction system under alcohol reflux, which is a method for producing a magnesium alcoholate characterized in that a mixture of metallic magnesium, an alcohol, and at least one of a halogen or a halogen atom-containing compound is added to the reaction system at each portionwise addition.

TECHNICAL FIELD

The present invention relates to a method for producing a magnesiumalcoholate used for preparing a solid catalyst component for olefinpolymerization or the like.

Priority is claimed on Japanese Patent Application No. 2011-229527,filed Oct. 19, 2011, the content of which is incorporated herein byreference.

BACKGROUND ART

As a solid catalyst component for olefin polymerization, sphericalmagnesium alcoholates having an average particle diameter of 60 μm ormore, a less number of fine particles, and a sufficient strength havebeen desired. As a method for producing such magnesium alcoholates, forexample, there is a method disclosed in Patent Document 1 that the finalratio of the metallic magnesium and alcohol used in the reaction systemis from ¼ to 1/25 in mass ratio, and that particulate metallic magnesiumhaving a diameter of not more than 500 μm and the alcohol are addedcontinuously or intermittently in a portionwise manner to the reactionsystem under alcohol reflux and allowed to react for 100 to 1,200minutes. In addition, in this method, it has been described that it ispreferable to carry out the addition of each of the metallic magnesiumand alcohol in 10 or more separate portions, and also in a manner sothat the intervals of addition is a combination of intervals selectedarbitrarily from the range of 10 to 120 minutes and the total additiontime is within the range of not more than 1,200 minutes. It has beendescribed that by using this method, particulate matter ofdialkoxymagnesium having spherical or ellipsoidal particle shapes withan average particle diameter represented by D₅₀ in the range of 60 to200 μm, a bulk specific gravity of 0.2 to 0.7 g/ml, numerous internalpores with pore sizes from 0.1 to 5 μm as determined by TEM observation,and a particle size distribution represented by (D₉₀−D₁₀)/D₅₀ of notmore than 1, can be obtained, and the breaking strength of theaggregated particulate matter is from 0.5 to 10 MPa. It has beendescribed that in the synthetic reaction according to this method, theuse of a catalyst is preferred, while listing iodine and the like asexamples of useful catalysts, and moreover, this catalyst may beinitially added collectively to the reaction system or may be addedwhile adjusting the amount in accordance with the portionwise additionof raw materials.

Further, it has been disclosed in Patent Document 2 that by reactingmetallic magnesium, an alcohol, and 0.0001 gram atom or more of ahalogen or halogen-containing compound containing a halogen, relative toone gram atom of the above metallic magnesium, it is possible to producean alkoxy group-containing magnesium compound having an average particlediameter from 1 to 300 μm and also a particle size distribution index(P) represented by the following formula (1) of P<5.0 which indicates anarrow particle size distribution, and which can be used as it iswithout particle size adjusting treatments such as pulverization andclassification (formula (1): P=D₉₀/D₁₀, where D₉₀ denotes a particlediameter corresponding to the cumulative weight fraction of 90%, and D₁₀denotes a particle diameter corresponding to the cumulative weightfraction of 10%). In this document, it has been described that there isno need to introduce the total amount of each of metallic magnesium, analcohol, and a halogen and/or halogen-containing compound into areaction tank from the beginning, and the introduction may be conductedin separate portions.

CITATION LIST Patent Documents

Patent Document 1: Japanese Unexamined Patent Application, FirstPublication No. 2007-297371

Patent Document 2: Japanese Unexamined Patent Application, FirstPublication No. Hei 4-368391

SUMMARY OF INVENTION Technical Problem

Among all the known magnesium alcoholates described above, althoughthose having a particle size distribution represented by (D₉₀−D₁₀)/D₅₀of not greater than 1 have been known, those having an even smallerdistribution of less than 0.78 have not been known, and thus themagnesium alcoholates with an even smaller particle size distributionhave been desired. In addition, those having an average particlediameter represented by D₅₀ of less than 60 μm and a particle sizedistribution represented by (D₉₀−D₁₀)/D₅₀ of not greater than 1 have notbeen known either, and thus the magnesium alcoholates having a smallparticle size distribution even when the particle size is small havealso been desired.

Further, in Patent Document 1, although it has been described that thecatalyst used may be added to the reaction system while adjusting theamount in accordance with the portionwise addition of the raw materials,it has been suggested that in those cases where the frequency ofportionwise addition of the raw materials is low, for example, when itis about four to five times, the desired product (magnesium alcoholateshaving an average particle diameter represented by D₅₀ of 60 to 200 μmand also a particle size distribution represented by (D₉₀−D₁₀)/D₅₀ ofnot greater than 1) cannot be obtained.

In addition, in Patent Document 2, it has been described that thesuitable frequency of portionwise additions is 5 to 10 times, and that amethod is preferred in which the total amount of an alcohol is addedfrom the beginning and metallic magnesium is then divided into severalportions and added.

Furthermore, there are neither descriptions nor suggestions, in bothPatent Documents 1 and 2, on a specific method for portionwise addition,for example, the way the portionwise addition is carried out and theoptimal ratio of each of the raw materials that are added in aportionwise manner.

The aim of the present invention is to provide a spherical orellipsoidal magnesium alcoholate having a narrow particle sizedistribution even when the particle size is small.

Solution to Problem

As a result of intensive studies in order to solve the above problems,the inventors of the present invention found that it is possible tosolve the above problems by always adding a mixture containing metallicmagnesium, an alcohol, and a halogen or halogen atom-containing compoundat each portionwise addition, thereby leading to completion of thepresent invention.

That is, the present invention relates to a method for producing amagnesium alcoholate by adding in a portionwise manner to a reactionsystem and reacting, metallic magnesium, an alcohol, and at least one ofa halogen or a halogen atom-containing compound under alcohol reflux,which is a method for producing a magnesium alcoholate characterized inthat a mixture of metallic magnesium, an alcohol, and at least one of ahalogen or a halogen atom-containing compound is added to the reactionsystem at each portionwise addition.

In the method for producing a magnesium alcoholate according to thepresent invention, it is preferable that the frequency of portionwiseaddition of the aforementioned mixture be set to less than 10 times; itis preferable that the mass ratio of metallic magnesium and alcohol andthe mass ratio of metallic magnesium and halogen or halogenatom-containing compound in the aforementioned mixture added portionwisebe substantially constant at each portionwise addition; and moreover, itis preferable that the interval between the portionwise additions beconstant.

Advantageous Effects of Invention

By using the method for producing a magnesium alcoholate according tothe present invention, it is possible to obtain a magnesium alcoholatehaving an unprecedented quality in which the particle size distribution,particle diameter, and particle type are controlled.

In other words, by this production method, it is possible to produce amagnesium alcoholate as a particulate matter having a particle sizedistribution represented by (D₉₀−D₁₀)/D₅₀ of less than 0.78 and aspherical or ellipsoidal particle shape, or a magnesium alcoholate inthe form of a particulate matter having an average particle diameterrepresented by D₅₀ of less than 60 μm, a particle size distributionrepresented by (D₉₀−D₁₀)/D₅₀ of not greater than 1, and a spherical orellipsoidal particle shape.

By preparing a catalyst for olefin polymerization using the magnesiumalcoholate obtained by this method in which the particle sizedistribution, particle diameter, and particle type are controlled, anolefin polymer can be obtained in which the particle size distribution,particle diameter, and particle type are controlled.

DESCRIPTION OF EMBODIMENTS

The values D₁₀, D₅₀, and D₉₀ used in the present invention denote theparticle diameters at 10%, 50%, and 90%, in terms of cumulative particlesize. That is, for example, D₁₀ indicates a particle diameter at thetime when the particle size distribution of the particulate matter ismeasured and the integrated value of the mass of the particulate matterreached 10% by mass. Accordingly, D₅₀ denotes an intermediate value ofthe particle diameter of the entire particulate matter, and thus thisindicates the average particle diameter.

<Method for Producing Magnesium Alcoholate>

A method for producing a magnesium alcoholate according to the presentinvention (production method of the present invention) is a method forproducing a magnesium alcoholate by adding in a portionwise manner to areaction system and reacting, metallic magnesium, an alcohol, and atleast one of a halogen or a halogen atom-containing compound underalcohol reflux, which is characterized in that a mixture of metallicmagnesium, an alcohol, and at least one of a halogen or a halogenatom-containing compound is added to the reaction system at eachportionwise addition.

The metallic magnesium used in the production method of the presentinvention may be in any form as long as the reactivity is favorable. Inother words, any of those having a granular, ribbon or powder form canbe used. However, it should be noted that from the viewpoint ofreactivity, the degree of oxidation at the surface of metallic magnesiumparticles is preferably as low as possible, and those in which magnesiumoxide is formed on the surface are not preferable for use. Therefore,for example, those stored under the atmosphere of an inert gas such asnitrogen, and those having a metal surface treated with a solvent thatdoes not adversely affect the reaction to prevent surface oxidation arepreferred.

In order to set the average particle diameter of the magnesiumalcoholate to be produced from 10 to 50 μm, the particle size of theused metallic magnesium is preferably not greater than 350 μm, and morepreferably from 88 to 350 μm. The metallic magnesium having a particlesize within this range is suitable in terms of maintaining uniformreactivity.

In addition, in order to set the average particle diameter of themagnesium alcoholate to be produced to 60 μm or greater, it ispreferable to use a metallic magnesium in the form of a particulatematter having a particle size of not greater than 500 μm, and it is morepreferable to use a metallic magnesium in the form of a particulatematter composed of fine particles having an average particle diameterrepresented by D₅₀ of 50 to 500 μm and a particle size distributionrepresented by (D₉₀−D₁₀)/D₅₀ of not more than 2. The form of theparticulate matter may be a powder form.

Any alcohol can be used as the alcohol used in the production method ofthe present invention, but it is preferable to use a lower alcohol of 1to 6 carbon atoms. In particular, it is preferable to use ethanolbecause magnesium compounds with significantly improved catalyticperformance can be obtained.

Although the purity and water content of alcohol are not limited, thosewith a low water content are preferred. More specifically, it ispreferable to use an alcohol having a water content of not more than 1%,and it is more preferable to use an alcohol having a water content ofnot more than 2,000 ppm. When an alcohol with a high water content isused, magnesium hydroxide tends to form easily on the surface ofmetallic magnesium. Further, in order to obtain a magnesium alcoholatehaving a more favorable morphology, the water content in an alcohol ispreferably as low as possible, and in general, it is preferably not morethan 200 ppm.

The ratio of metallic magnesium and alcohol used at the time ofcompleting the addition of the entire amount of raw materials to thereaction system is preferably from ¼ to 1/25 in terms of mass ratio. Bysetting the amount of alcohol to not less than 4 relative to the amountof metallic magnesium, the reaction can be allowed to proceedsufficiently, the remaining of unreacted magnesium can be suppressed,and the particle diameter can be controlled easily to achieve the targetvalue. In addition, by setting the amount of alcohol to not more than 25relative to the amount of metallic magnesium, the amount of alcoholincorporated in the product formed in the reaction (particulate productsare mainly formed) can be reduced. As a result, it is possible tosuppress the number of voids generated when the alcohol in the productis removed by evaporation by a drying treatment, and to prevent the bulkspecific gravity from becoming too small.

Although the type of halogen used in the production method of thepresent invention is not particularly limited, chlorine, bromine, oriodine is preferred, and in particular, iodine is suitably used.

In addition, there is no limitation on the type of halogenatom-containing compound used in the production method of the presentinvention either, and any compounds can be used as long as they arecompounds containing a halogen atom within the chemical formula thereof.More specifically, examples thereof include MgCl₂, Mg(OEt)Cl, Mg(OEt)I,MgBr₂, CaCl₂, NaCl, and KBr, and among these, it is preferable to useMgCl₂ or MgI₂. The state, shape, particle size or the like of thehalogen or halogen atom-containing compound added to the reaction systemare not particularly limited, and any of those may be selected. Forexample, those in the form of a solution dissolved in an alcohol-basedsolvent such as ethanol can be used.

The amount of halogen or halogen atom-containing compound used in theproduction method of the present invention is not particularly limitedas long as the amount is sufficient for the reaction with metallicmagnesium and alcohol, but is preferably not less than 0.0001 gram atom,more preferably not less than 0.0005 gram atom, and even more preferablynot less than 0.001 gram atom, relative to 1 gram atom of metallicmagnesium, at the time when the addition of the entire amount of rawmaterials to the reaction system is completed. The halogen or halogenatom-containing compound acts as a catalyst for the reaction withmetallic magnesium and alcohol, and it is preferable to adjust the totalamount added and the amount added at the time of each portionwiseaddition to the reaction system in accordance with the portionwiseaddition of other raw materials.

In the present invention, each of the halogen and halogenatom-containing compound may be used alone, or two or more types thereofmay be used in combination. In addition, it is also possible to use ahalogen and a halogen atom-containing compound concurrently. When usedin combination, at the time when the addition of the entire amount ofraw materials to the reaction system is completed, the amount of totalhalogen in the reaction system is preferably not less than 0.0001 gramatom, more preferably not less than 0.0005 gram atom, and even morepreferably not less than 0.001 gram atom, relative to 1 gram atom ofmetallic magnesium.

The upper limit for the use amount of halogen and/or halogenatom-containing compound added to the reaction system is notparticularly limited, but is preferably less than 0.06 gram atom,relative to 1 gram atom of metallic magnesium.

The raw materials such as metallic magnesium, alcohol, and at least oneof a halogen or a halogen atom-containing compound are divided into twoor more portions and added to the reaction system. The portionwiseaddition of raw materials to the reaction system is conducted under thereflux of an alcohol-based solvent, preferably the same alcohol as theraw material. In the production method of the present invention, themixture added in a portionwise manner must contain all three types ofmaterials, that is, metallic magnesium, an alcohol, and at least one ofa halogen or a halogen atom-containing compound. By newly adding, notonly metallic magnesium and an alcohol, but also a halogen or halogenatom-containing compound to the reaction system at each portionwiseaddition, the particle density (apparent specific gravity) can beincreased, and moreover, the amount of amorphous fine particles can bereduced, and accompanied with this, the yield of the product can beincreased. Although the frequency of portionwise addition of theaforementioned mixture to the reaction system is not particularlylimited as long as it is not less than twice, the addition is preferablyconducted by dividing the mixture into 2 or more portions but less than10 portions, and more preferably it is conducted by dividing the mixtureinto 2 to 5 portions.

The mixture added to the reaction system at the time of portionwiseaddition may be any one of those containing all of metallic magnesium,an alcohol and at least one of a halogen or a halogen atom-containingcompound. That is, in the aforementioned mixture, the mass ratio ofmetallic magnesium and alcohol and the mass ratio of metallic magnesiumand halogen and/or halogen atom-containing compound are not particularlylimited, and may be different at each portionwise addition, or themixtures having the same composition may be added at the time of all theportionwise additions. Further, the portionwise addition may beperformed with a material ratio different from the final addition ratio(the ratio between the total added amounts to the reaction system). Forexample, it is possible to increase the ratio of metallic magnesium inthe early stage of the reaction from the final addition ratio anddecrease the ratio of metallic magnesium added in the later stage. Inthe production method of the present invention, it is preferable to setthe mass ratio of metallic magnesium and alcohol and the mass ratio ofmetallic magnesium and halogen or halogen atom-containing compound inthe aforementioned mixture that is added in a portionwise manner to besubstantially constant at each portionwise addition.

Further, the amount of mixture added to the reaction system in oneportionwise addition is also not particularly limited, and may bedifferent at each portionwise addition, or substantially the same amountof mixture may be added to the reaction system at each portionwiseaddition.

For example, the addition may be conducted by sequentially increasingthe added amount. In the production method of the present invention, itis preferable to add a constant amount of mixture every time.

In the production method of the present invention, it is preferable toadd the raw materials so that the following synthetic reaction isallowed to proceed only after the primary particles of thedialkoxymagnesium produced in the reaction system deposit on thedialkoxymagnesium that is already present in the system. The interval ofthe portionwise addition differs depending on other conditions such asthe size of the reaction apparatus and the temperature, but ispreferably adjusted so as to be an interval of 10 to 120 minutes. Inother words, it is preferable to add the next raw material at a stagewhere dialkoxymagnesium is produced by the reaction and the generationof H₂ is almost completed (stage where unreacted metallic magnesium issubstantially absent) after the portionwise addition in the previousstage. It is preferable to add, at the time point where the reaction ofadded magnesium is almost completed, the next portion of magnesium, andit is preferable to add, so that the final ratio of metallic magnesiumand alcohol be within the range from ¼ to 1/25 in terms of weight ratio.

Note that in order to allow the reaction to proceed smoothly, it ispreferable to react metallic magnesium in a relatively small amount ofalcohol at an early stage of the reaction, and to adjust theconcentration by further adding alcohol after adding all of metallicmagnesium.

The interval of the portionwise addition of the aforementioned mixtureto the reaction system is not particularly limited, and can be adjustedas appropriate by taking into consideration the amount, composition, orthe like of the mixture that is added in a portionwise manner. In theproduction method of the present invention, it is preferable tosequentially add at a constant interval.

By the addition interval of the mixture described above, the D₅₀ valueof the obtained magnesium alcoholate can be controlled. For example, itis possible to obtain a magnesium alcoholate having a small particlesize by shortening the addition interval, and it is possible to obtain amagnesium alcoholate having a large particle size by increasing theaddition interval, respectively.

Although the total reaction time depends on the scale thereof, the timepoint at which the reaction is completed can be determined by thecompletion of hydrogen generation.

After the final addition of the aforementioned mixture, it is preferableto further conduct an aging process at a temperature from 70° C. to thereflux temperature of the solvent, following the completion of hydrogengeneration, to thereby stabilize the produced particles. The aging timecan be altered as appropriate in accordance with the intended particlediameter, particle size distribution and bulk specific gravity ofmagnesium alcoholate. The reaction temperature at the time of aging maybe from 70° C. to the reflux temperature of the solvent, and thestirring speed is from 50 to 500 rpm, and the reaction temperature andthe stirring speed can be selected in accordance with the intendedparticle diameter, particle size distribution and bulk specific gravityof magnesium alcoholate.

More specifically, by reducing the stirring speed (the transfer rate ofthe reaction solution), the particle diameter of magnesium alcoholatecan be increased, and by increasing the stirring speed, the particlediameter of magnesium alcoholate can be decreased.

<Magnesium Alcoholate>

According to the production method of the present invention, a magnesiumalcoholate in which the particle size distribution, particle diameterand particle type are controlled can be produced. For example, it ispossible to produce a magnesium alcoholate in the form of particulatematter having the D₅₀ particle diameter within the range from 10 to 200μm, in particular, particulate matter having a large particle diameterfrom 80 to 200 μm which enables the omission of a pelleting process atthe time of molding the olefin polymers produced when used in apolymerization catalyst.

In addition, according to the production method of the presentinvention, a magnesium alcoholate can be produced as particulate matterhaving a relatively uniform particle diameter distribution. For example,it is possible to obtain particulate matter of a magnesium alcoholatehaving a particle size distribution represented by (D₉₀−D₁₀)/D₅₀ of notmore than 1, preferably less than 0.78. In particular, even when the D₅₀particle size is less than 60 μm, it is possible to make theaforementioned value of particle size distribution to less than 1.

That is, the magnesium alcoholate according to the present invention ischaracterized as being a particulate matter with a particle sizedistribution represented by (D₉₀−D₁₀)/D₅₀ of less than 0.78 and having aspherical or ellipsoidal particle shape. In addition, as another aspect,the magnesium alcoholate according to the present invention ischaracterized as being a particulate matter having an average particlediameter represented by D₅₀ of less than 60 μm, a particle sizedistribution represented by (D₉₀−D₁₀)/D₅₀ of not more than 1, and aspherical or ellipsoidal particle shape.

Further, the magnesium alcoholate of the present invention may becomposed of porous aggregates of the spherical, ellipsoidal, scale-like,or needle-like primary particles of magnesium alcoholate having aparticle diameter of 1 to 10 μm, and preferably does not substantiallycontain particles having a particle diameter of 10 μm or less. The porespresent inside the particulate matter and having a pore diameter of 0.1to 5 μm as observed by a transmission electron microscope (TEM) arethought to be those composed of gaps between the particles that areformed when the primary particles aggregated as described above. Whenthese gaps between the particles become 10 μm or greater, there are somecases where the bonds between the primary particles are weak, therebymaking the strength of the particulate matter insufficient.

As described above, the magnesium alcoholate of the present invention isa particulate matter having a narrow particle size distribution and aspherical or ellipsoidal particle shape even when the particle size issmall. For this reason, in particular, it can be used suitably as asolid catalyst component for olefin polymerization.

In order to prepare a catalyst for olefin polymerization by using themagnesium alcoholate of the present invention as a starting material,the magnesium alcoholate (particulate matter of dialkoxymagnesium) isbrought into contact with a halide of tetravalent titanium and anelectron donating compound by a known method to produce a catalystcomponent, and then an organic aluminum compound is allowed to actthereon. Examples of the halide of tetravalent titanium include titaniumtetrachloride and alkoxy titanium halides. Examples of the electrondonating compounds include alcohols, ethers, esters, and organic siliconcompounds such as alkoxysilane. Examples of the aluminum compoundsinclude triethylaluminum and diethylalminum chloride.

EXAMPLES

A more detailed description of the present invention is presented belowbased on a series of examples, although the present invention is in noway limited by these examples.

Example 1

A reflux condenser connected with an integrating-type gas meter, athermometer, a dropping funnel for ethanol, as well as a nitrogen inlettube interposed with a gas flow meter were installed onto a 500 mlfour-necked flask equipped with a stirrer. After sufficiently replacingthe inside of the reaction system with nitrogen, 60 g of anhydrousethanol (water content: 200 ppm) and 0.4 g of iodine were charged anddissolved therein. 6.1 g of metallic magnesium (particle size: 300 to149 μm) was charged thereinto, and under stirring at a stirringintensity of 2.60×10¹¹ rpm³·mm₂, the temperature was raised up to thereflux temperature of the alcohol in an oil bath. The reaction wasstabilized within 10 minutes from the charging of the metallicmagnesium, and thereafter, 40 g of ethanol, 6.1 g of metallic magnesiumand 0.3 g of iodine were charged at a time every 10 minutes and in threeseparate portions to allow the reaction to continue. The total amount ofthe charged metallic magnesium was 24.4 g, and the amount of ethanolused at this point was 180 g. Further, when 183 g of ethanol of the samequality as that of the one used earlier was added dropwise over 1 hourto allow the ageing reaction to continue until no hydrogen gas wasdetectable in the exhaust gas, it took 8 hours in total from the initialcharging.

The ethanol/metallic magnesium ratio (mass ratio of the total amount ofethanol and the total amount of metallic magnesium that were chargedinto the reaction system) was 16/1. After the completion of thereaction, the liquid in the reaction system was dried under reducedpressure in a rotary evaporator to obtain 107 g (yield: 94%) ofmagnesium ethylate. As a result of observing the thus obtained magnesiumethylate using a scanning electron microscope (JSM-5300 manufactured byJEOL Ltd. DATUM Solution Business Operations) at 1,000-foldmagnification with an accelerating voltage of 20 kV, subsphericalparticles made of those, each one of which is a strip-like particle,that were densely overlapping were obtained, although the particlesurface was smooth. The degree of sphericity (S) as determined from thepictures taken was 1.01. When the particle size distribution wasmeasured using a laser diffraction type particle size distributionmeasuring apparatus (HELOS & RODOS manufactured by Sympatec GmbH), D₅₀was 40.98 μm, D₁₀ was 25.14 μm, D₉₀ was 55.58 μm, and the particle sizedistribution had a narrow distribution width of 0.743. In addition, themeasurement result of bulk specific gravity (looseness) (apparentspecific gravity) was 0.301 g/ml. The above results are summarized andshown in Table 2.

Examples 2 to 7

The measurements in these Examples were carried out in the same manneras in Example 1 with the exception that the numerical valuescorresponding to each of the conditions used in Example 1 were changedto the numerical values set forth in Table 1. The results are summarizedand shown in Table 2. In Table 1, “Mg” represents magnesium, “I”represents iodine, and “frequency” of the “portionwise addition”represents the frequency of portionwise addition, respectively.

TABLE 1 Total amount Amount of portionwise addition (g) StirringAddition used (g) Charging Portionwise addition intensity interval Mg IMg I Mg I Frequency (rpm³ · mm₂) (minutes) Ex. 1 24.4 1.3 6.1 0.4 6.10.3 3 2.60 × 10¹¹ 10 Ex. 2 18.4 1.3 6.1 0.4 4.1 0.3 3 2.60 × 10¹¹ 10 Ex.3 24.4 1.5 6.1 0.6 6.1 0.3 3 2.60 × 10¹¹ 15 Ex. 4 24.4 1.5 6.1 0.6 6.10.3 3 1.60 × 10¹¹ 15 Ex. 5 24.4 1.5 6.1 0.6 6.1 0.3 3 1.60 × 10¹¹ 20 Ex.6 24.4 1.98 6.1 0.6 6.1 0.46 3 6.75 × 10¹⁰ 20 Ex. 7 24.4 1.98 6.1 0.66.1 0.46 3 6.75 × 10¹⁰ 20

TABLE 2 Product Particle size Apparent specific yield (%) D₅₀ (μm)distribution gravity (g/ml) Example 1 93.8 40.98 0.743 0.301 Example 293.2 46.64 0.536 0.311 Example 3 94.5 48.49 0.501 0.295 Example 4 96.351.75 0.566 0.291 Example 5 94.8 67.77 0.511 0.301 Example 6 93.5 73.830.562 0.31 Example 7 94.0 71.34 0.487 0.301

Example 8

A reflux condenser connected with an integrating-type gas meter, athermometer, a dropping funnel for ethanol, as well as a nitrogen inlettube interposed with a gas flow meter were installed onto a 500 mlfour-necked flask equipped with a stirrer. After sufficiently replacingthe inside of the reaction system with nitrogen, 100 g of anhydrousethanol (water content: 200 ppm) and 0.6 g of iodine were charged anddissolved therein. 8.1 g of metallic magnesium (particle size: 300 to149 μm) was charged thereinto, and under stirring, the temperature wasraised up to the reflux temperature of the alcohol in an oil bath. Sincethe reaction was stabilized within 10 minutes from the charging of themetallic magnesium, 10 g of ethanol, 4.1 g of metallic magnesium, and0.3 g of iodine were additionally added after 10 minutes from the pointof charging the metallic magnesium, and after another 10 minutes, 40 gof ethanol, 7.1 g of metallic magnesium, and 0.2 g of iodine wereadditionally added, and after another 10 minutes, 30 g of ethanol, 5.1 gof metallic magnesium, and 0.1 g of iodine were additionally added,thereby dividing the addition into three separate portions to allow thereaction to continue. The total amount of the charged metallic magnesiumwas 24.4 g, and the amount of ethanol used at this point was 180 g.Further, when 183 g of ethanol of the same quality as that of the oneused earlier was added dropwise over 1 hour to allow the ageing reactionto continue until no hydrogen gas was detectable in the exhaust gas, ittook 5 hours in total from the initial charging.

The ethanol/metallic magnesium ratio was 15/1. After the completion ofthe reaction, the liquid in the reaction system was dried under reducedpressure in a rotary evaporator to obtain 105 g (yield: 92.1%) ofmagnesium ethylate. When the particle size distribution was measured inthe same manner as in Example 1, D₅₀ was 48.34 μm, D₁₀ was 36.36 μm, d₉₀was 60.12 μm, and the particle size distribution had a narrowdistribution width of 0.492. In addition, the measurement result of bulkspecific gravity (looseness) was 0.288 g/ml.

Example 9

A reflux condenser connected with an integrating-type gas meter, athermometer, a dropping funnel for ethanol, as well as a nitrogen inlettube interposed with a gas flow meter were installed onto a 500 mlfour-necked flask equipped with a stirrer. After sufficiently replacingthe inside of the reaction system with nitrogen, 60 g of anhydrousethanol (water content: 200 ppm) and 0.4 g of iodine were charged anddissolved therein. 6.1 g of metallic magnesium (particle size: 210 to149 μm) was charged thereinto, and under stirring, the temperature wasraised up to the reflux temperature of the alcohol in an oil bath. Sincethe reaction was stabilized within 10 minutes from the charging of themetallic magnesium, 40 g of ethanol, 6.1 g of metallic magnesium, and0.3 g of iodine were additionally added after 10 minutes from the pointof charging the metallic magnesium, and after another 15 minutes, 40 gof ethanol, 6.1 g of metallic magnesium, and 0.3 g of iodine wereadditionally added, and after another 5 minutes, 40 g of ethanol, 6.1 gof metallic magnesium, and 0.3 g of iodine were additionally added,thereby dividing the addition into three separate portions to allow thereaction to continue.

The total amount of the charged metallic magnesium was 24.4 g, and theamount of ethanol used at this point was 180 g. Further, when 183 g ofethanol of the same quality as that of the one used earlier was addeddropwise over 1 hour to allow the ageing reaction to continue until nohydrogen gas was detectable in the exhaust gas, it took 5 hours in totalfrom the initial charging.

The ethanol/metallic magnesium ratio was 15/1. After the completion ofthe reaction, the liquid in the reaction system was dried under reducedpressure in a rotary evaporator to obtain 107 g (yield: 93.8%) ofmagnesium ethylate. When the particle size distribution was measured inthe same manner as in Example 1, D₅₀ was 57.1 μm, D₁₀ was 43.03 μm, D₉₀was 71.06 μm, and the particle size distribution had a narrowdistribution width of 0.491. In addition, the measurement result of bulkspecific gravity (looseness) was 0.319 g/ml.

Examples 10 to 27

The measurements in these Examples were carried out in the same manneras in Example 1 with the exception that the numerical valuescorresponding to each of the conditions used in Example 1 were changedto the numerical values set forth in Table 3. The results are summarizedand shown in Table 4.

In Example 17, the amount of ethanol used was 183 g at the time ofcharging and was 120 g at the time of each portionwise addition, theamount of ethanol at the point where all of the charging had beencompleted was 543 g, and another 549 g was further added as a diluent.

TABLE 3 Metallic Mg apparent Total specific amount Amount of portionwiseaddition (g) Stirring Addition gravity used (g) Charging Portionwiseaddition intensity interval (g/ml) Mg I Mg I Mg I Frequency (rpm³ · mm₂)(minutes) Ex. 10 0.838 24.4 1.3 6.1 0.4 6.1 0.3 3 2.60 × 10¹¹ 10 Ex. 110.838 24.4 1.3 6.1 0.4 6.1 0.3 3 6.75 × 10¹⁰ 10 Ex. 12 0.838 24.4 1.36.1 0.4 6.1 0.3 3 2.60 × 10¹¹ 20 Ex. 13 0.838 24.4 1.3 6.1 0.4 6.1 0.3 36.75 × 10¹⁰ 20 Ex. 14 0.855 24.4 1.3 6.1 0.4 6.1 0.3 3 2.60 × 10¹¹ 10Ex. 15 0.855 24.4 1.3 6.1 0.4 6.1 0.3 3 6.75 × 10¹⁰ 10 Ex. 16 0.855 24.41.98 6.1 0.6 6.1 0.46 3 2.60 × 10¹¹ 15 Ex. 17 0.855 73.2 5.94 18.3 1.818.3 1.38 3 6.75 × 10¹⁰ 15 Ex. 18 0.855 24.4 1.3 6.1 0.4 6.1 0.3 3 2.60× 10¹¹ 25 Ex. 19 0.769 24.4 1.3 6.1 0.4 6.1 0.3 3 2.60 × 10¹¹ 10 Ex. 200.769 24.4 1.3 6.1 0.4 6.1 0.3 3 1.60 × 10¹¹ 10 Ex. 21 0.769 24.4 1.36.1 0.4 6.1 0.3 3 2.60 × 10¹¹ 15 Ex. 22 0.769 24.4 1.3 6.1 0.4 6.1 0.3 31.60 × 10¹¹ 15 Ex. 23 0.769 24.4 1.3 6.1 0.4 6.1 0.3 3 1.60 × 10¹¹ 15Ex. 24 0.769 24.4 1.3 6.1 0.4 6.1 0.3 3 2.60 × 10¹¹ 20 Ex. 25 0.769 24.41.3 6.1 0.4 6.1 0.3 3 1.60 × 10¹¹ 20 Ex. 26 0.769 24.4 1.3 6.1 0.4 6.10.3 3 6.75 × 10¹⁰ 20 Ex. 27 0.769 24.4 1.3 6.1 0.4 6.1 0.3 3 6.75 × 10¹⁰25

TABLE 4 Product Particle size Apparent specific yield (%) D₅₀ (μm)distribution gravity (g/ml) Example 10 94.3 57.1 0.458 0.27 Example 1194.6 67.51 0.459 0.302 Example 12 95.1 67.62 0.467 0.303 Example 13 96.376.58 0.539 0.292 Example 14 93.2 46.64 0.536 0.311 Example 15 96.857.75 0.466 0.27 Example 16 88.7 55.74 0.807 0.29 Example 17 93.1 64.260.523 0.3 Example 18 97.3 59.19 0.513 0.26 Example 19 94.3 45.15 0.5530.302 Example 20 94.3 50.54 0.578 0.303 Example 21 99.11 48.72 0.4850.28 Example 22 96.3 51.75 0.566 0.291 Example 23 94.2 52.9 0.571 0.293Example 24 93.8 51.2 0.576 0.32 Example 25 95.7 54.43 0.521 0.296Example 26 92 58.63 0.481 0.283 Example 27 93.1 60.33 0.521 0.298

Comparative Example 1

Using the same apparatus as in Example 1, 181 g of anhydrous ethanol,1.3 g of iodine, and 24.4 g of metallic magnesium (350 to 210 μm) werecharged thereto, and the temperature was raised under alcohol reflux toinitiate the reaction. The aging reaction was conducted for 5 hours tocomplete the reaction. The particles obtained by drying had a degree ofsphericity (S) of 1.25, D₅₀ was 46.69 μm, D₁₀ was 24.23 μm, D₉₀ was70.87 μm, the particle size distribution had a wide distribution widthof 0.999, the particle surface was not dense, and the degree ofsphericity was somewhat low with a large number of irregularities. Inaddition, the bulk specific gravity (looseness) was 0.203 g/ml.

Comparative Example 2

A 500 ml four-necked, round-bottom flask was mounted with a stirringdevice, a dropping funnel and a thermometer, and 61 g of ethanol, 1.3 gof iodine and 6.1 g of granular metallic magnesium were first chargedthereto under a stream of nitrogen, and were heated to reflux at a bathtemperature of 80° C. After 10 minutes, 40 g of ethanol and 6.1 g ofmetallic magnesium were additionally added, and after another 10minutes, 40 g of ethanol and 6.1 g of metallic magnesium wereadditionally added, and after another 10 minutes, 40 g of ethanol and6.1 g of metallic magnesium were additionally added, and after another10 minutes, 185 g of ethanol was added dropwise over 1 hour, followed by5 hours of aging process to complete the reaction. Then, after beingcooled to room temperature, ethanol was removed by evaporation underreduced pressure, followed by drying to obtain 79.9 g of magnesiumethylate (yield: 75.9%), which was the intended product.

The thus obtained particles had a D₅₀ of 46.69 μm, a D₁₀ of 24.23 μm,and a D₉₀ of 70.87 μm, and the particle size distribution had a widedistribution of 0.999. The bulk specific gravity (looseness) was a smallvalue of 0.203 g/ml.

INDUSTRIAL APPLICABILITY

By using the method for producing a magnesium alcoholate according tothe present invention, it is possible to obtain a magnesium alcoholatehaving an unprecedented quality in which the particle size distribution,particle diameter, and particle type are controlled.

By preparing a catalyst for olefin polymerization using the magnesiumalcoholate obtained by this method, an olefin polymer can be obtained inwhich the particle size distribution, particle diameter, and particletype are controlled. From the above results, the present invention isextremely useful industrially.

1. A method for producing a magnesium alcoholate comprising: adding in aportionwise manner to a reaction system and reacting, metallicmagnesium, an alcohol, and at least one of a halogen or a halogenatom-containing compound in a reaction system under alcohol reflux,wherein a mixture of metallic magnesium, an alcohol, and at least one ofa halogen or a halogen atom-containing compound is added to the reactionsystem at each portionwise addition.
 2. The method for producing amagnesium alcoholate according to claim 1, wherein a frequency ofportionwise addition of said mixture is less than 10 times.
 3. Themethod for producing a magnesium alcoholate according to claim 1,wherein a mass ratio of metallic magnesium and alcohol and a mass ratioof metallic magnesium and halogen or halogen atom-containing compound insaid mixture that is added in a portionwise manner is set to besubstantially constant at each portionwise addition.
 4. The method forproducing a magnesium alcoholate according to claim 1, wherein aninterval of portionwise addition of said mixture is set to besubstantially constant.
 5. The method for producing a magnesiumalcoholate according to claim 1, wherein the halogen or thehalogen-containing compound is reacted in an amount of 0.0001 gram atomor more, relative to one gram atom of the metallic magnesium. 6-7.(canceled)